Field of the Invention
The present disclosure relates to a member for electrophotography for use in an electrophotographic apparatus and a process cartridge and an electrophotographic apparatus having the member for electrophotography.
Description of the Related Art
The member for electrophotography is a member to be used for various uses, such as a developer carrying member, a transfer member, a charging member, a developer feed member, a cleaning member, and a developer layer thickness regulation member. The member for electrophotography is sometimes provided with a surface layer on the surface from the viewpoint of high image quality and high durability. For example, in the case of the developer carrying member or the developer layer thickness regulation member, a surface layer containing urethane resin has been widely used due to excellent wear resistance and excellent charge-imparting performance to a developer.
However, in the member for electrophotography having such a surface layer, the adhesion of a developer to the surface has not been sufficiently controlled. When a large number of electrophotographic images have been formed using an electrophotographic apparatus having the member for electrophotography as a developer carrying member, for example, toner has adhered to the surface of the member for electrophotography, so that a toner thin film has been formed in some cases. Hereinafter, the phenomenon in which the toner thin film is formed may be referred to as toner filming in some cases.
Then, in order to prevent the toner filming, it has been proposed to contain fluorine atoms and silicon atoms having high releasability to a urethane resin.
Japanese Patent Laid-Open No. 2014-146010 has proposed a developing roller containing a reactant of a polyisocyanate prepolymer forming an isocyanurate and a compound having a functional group containing a fluorine atom or a silicone-based functional group as a resin component. Japanese Patent Laid-Open No. 2014-146010 describes that, in such a developing roller, the compound having the functional group containing a fluorine atom or the silicone-based functional group having low surface energy is segregated near the surface of the developing roller, and therefore the adhesion to toner can be reduced, whereby the toner filming with time can be prevented.
Moreover, Japanese Patent Laid-Open No. 2009-151141 has proposed a developing roller having a surface resin layer formed by curing a silicone graft fluororesin having a hydroxyl group with polyisocyanate.